Distal femoral cutting guide

ABSTRACT

A method of positioning a femoral cutting guide on a distal end of a femur establishes at least a first reference plane to perform a distal femoral planar cut. The method includes inserting a mounting member into an intramedullary canal of the femur and coupling a bridge member to the mounting member. The method also includes placing a cutting guide member over a medial anterior portion of the distal femur. The cutting guide member has a first channel that establishes the first reference plane. The bridge member has a bridge channel. A wall of the bridge channel is inserted into the first channel of the cutting guide member. A mounting mechanism generates resistance between the bridge member and the cutting guide member. The resistance is overcome by positioning the cutting guide member relative to the femur.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No.11/717,793 filed on Mar. 13, 2007. The entire disclosure of the aboveapplication is incorporated herein by reference.

FIELD

The present teachings relate to a cutting guide for resecting a portionof a bone and more particularly relate to a distal femoral cutting guidethat can be selectively adjusted over a medial anterior portion of adistal end of a femur.

BACKGROUND

A human joint 10 is the junction of four bones: a femur 12, a tibia 14,a fibula 16 and a patella 18, as shown in FIGS. 1-3. Myriad medicalproblems can require partial or complete replacement of one or moreportions of the aforesaid bones that form the knee joint 10. When usingone or more prosthetic devices to replace one or more portions of thebones of the knee joint 10, preparation portions of the various bonescan be necessary to supply a proper fit for the prosthetic. Preparationcan include resection or fashioning of the bones to complement aninterior portion of a prosthetic.

When implanting a prosthetic on a distal end 20 of the femur 12,portions of the distal end 20 can be resected to provide a proper fitfor the prosthetic. For example, a lateral condyle 22 and a medialcondyle 24 can be partially or completely resected in preparation forimplantation of the prosthetic. A distal femoral planar cut is generallyperformed relative to a mechanical angle of the knee joint 10. To varythe angle of the distal femoral planar cut, multiple componentstypically have to be disassembled and reassembled to provide the properangle. One or more of the components used to provide the distal femoralplanar cut are typically positioned above an anterior surface of thefemur. In such a position, access to an anterior portion of the femurand positioning components in the same area can be relatively difficult.While the above methods and components remain useful for their intendedpurpose, there remains room in the art for improvement.

SUMMARY

The present teachings generally include a system that locates a femoralcutting guide on a distal end of a femur. The femoral cutting guideestablishes at least a first reference plane to perform a distal femoralplanar cut. The system generally includes a mounting rod operable toinsert into the distal end of the femur. An index member is operable toabut the distal end of the femur. A bridge member extends from the indexmember. A cutting guide member extends from the bridge member. Thecutting guide member includes a first channel that establishes the firstreference plane. A mounting mechanism releasably couples the cuttingguide member to the bridge member. The mounting mechanism is operable togenerate a sliding resistance between the bridge member and the cuttingguide member that is generally overcome to position the cutting guidemember relative to the femur.

The present teachings provide a method of positioning a femoral cuttingguide on a distal end of a femur to establish at least a first referenceplane to perform a distal femoral planar cut. The method includesinserting a mounting member into an intramedullary canal of the femurand coupling a bridge member to the mounting member. The method alsoincludes placing a cutting guide member over a medial anterior portionof the distal femur. The cutting guide member has a first channel thatestablishes the first reference plane. The bridge member has a bridgechannel. A wall of the bridge channel is inserted into the first channelof the cutting guide member. A mounting mechanism generates resistancebetween the bridge member and the cutting guide member. The resistanceis overcome by positioning the cutting guide member relative to thefemur.

In some embodiments the method includes passing a mounting rod into akeyed bushing coupled to an offset opening through first and secondopposing surfaces of an index member and inserting the mounting rod intoan intramedullary canal of the femur. The method also includes insertingfirst and second elongated posts of a bridge member into correspondingfirst and second apertures in a peripheral wall of the index member andthe first and second elongated posts having different cross-sections andplacing a cutting guide member over a medial anterior corner of thedistal femur. The bridge member has a bridge channel. A wall of thebridge channel is inserted into a channel of the cutting guide member.The first surface of the index member is engaged to the distal end ofthe femur when the femur is a right femur. The second surface of theindex member is engaged to the distal end of the femur when the femur isa left femur.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present teachings.

DRAWINGS

The drawings described herein are for illustration purposes only and donot limit the scope of the present teachings.

FIG. 1 is a prior art partial front view of a knee joint showing bones,muscle tissue and connective tissue of the knee joint.

FIG. 2 is a prior art similar to FIG. 1 and shows a patella, the musclesand the associated connective tissue pulled away from respectiveportions of the knee joint.

FIG. 3 is a perspective view of the knee joint, absent the muscle andthe connective tissue, showing a lateral condyle, a medial condyle andan exemplary plane of resection of a distal end of the femur inaccordance with the present teachings.

FIG. 4 is an exploded assembly view of a distal femoral cutting guideassembly constructed in accordance with the present teachings having anindex member, a bridge member and a guide member that can couple to anintramedullary rod with a bushing coupled to the index member.

FIG. 5A is a partial perspective view of the bushing installed in theindex member and disposed over the intramedullary rod of FIG. 4 that isinstalled on the left femur in accordance with the present teachings.

FIG. 5B is similar to FIG. 5A and shows the bridge member connected tothe index member and receiving the guide member to hold the guide memberso that the cutting guide member can be further secured to the bone withsuitable fixation pins in a first set of apertures in accordance withthe present teachings.

FIG. 5C is similar to FIG. 5A and shows the cutting guide member securedto the femur with two fixation pins in the first set of apertures.

FIG. 5D is similar to FIG. 5C and shows the cutting guide member pulledoff the fixation pins and the femur without the need to remove thefixation pins from the left femur.

FIG. 5E is similar to FIG. 5C and shows the cutting guide member placedon the fixation pins that are received by additional apertures in thesecond set of apertures that position the cutting guide member in asuperior direction, i.e., up the left femur.

FIG. 5F is similar to FIG. 5E and shows the cutting guide member securedto the femur with the fixation pins through a second set and a third setof fixation apertures that can hold the cutting guide member to thefemur, while an exemplary resecting tool can make a cut using the guidechannels that establish a reference plane on which the resection can bebased.

FIG. 6 is a perspective view of the distal femoral cutting guideassembly showing the distal femoral cutting guide assembly installed ona right femur in accordance with the present teachings.

FIGS. 7A, 7B and 7C are each front views of different bushings showingthe angle at which an intramedullary rod that can be received within thebushing would be disposed relative to the index member.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present teachings, their application, or uses. Itshould be understood that throughout the drawings, correspondingreference numerals can indicate like or corresponding parts andfeatures.

The present teachings generally include a cutting guide assembly 100 forresecting a portion of a bone, as shown in FIG. 4. While the variousillustrated aspects of the present teachings pertain to the knee joint10 (FIG. 3) of the human body, it will be appreciated in light of thedisclosure that the teachings may also be applicable to various bones ofthe human body including, but not limited to, the tibia, the fibula, thehumerus, the ulna or the radius. It will also be appreciated that theteachings may be applicable to various bones of other animals, mammalianor otherwise, requiring replacement with prosthetics due to variousmedical concerns.

With reference to FIG. 4, the cutting guide assembly 100 can include anindex member 102, a bridge member 104 and a cutting guide member 106.The cutting guide assembly 100 can be used in a procedure to resect(i.e., surgically remove part of an organ or a structure) one or moreportions of a distal end of a right femur 12 a (FIG. 6) and/or a leftfemur 12 b (FIGS. 5A-5E), which can be collectively referred to as thedistal end 20 of the femur 12. As shown in FIG. 5A, the index member 102can abut the distal end 20 of the femur 12. As shown in FIG. 5B, thebridge member 104 can couple the cutting guide member 106 to the indexmember 102 and can establish a reference plane 108 (an imaginary plane,as shown in FIG. 4) that can project through the distal end 20 of thefemur 12. While the bridge member 104 is shown as a separate component,in one example, the bridge member 104 and the cutting guide member 106can be a single monolithic member or a collection of multiplecomponents.

In accordance with various aspects of the present teachings and withreference to FIG. 6, the cutting guide member 106 can be configured tobe located over a medial anterior corner of the distal end of a rightfemur 12 a. Moreover, the bridge member 104 can be configured to holdthe cutting guide member 106 over the medial anterior portion of thedistal end 20 of the femur 12. While holding the cutting guide member106, the bridge member 104 can be configured to provide a slidingresistance between the cutting guide member 106 and the bridge member104 in various aspects of the present teachings. The sliding resistancecan be overcome by the medical professional as he or she repositions thecutting guide member 106 relative to the bridge member 104, which willbe discussed in further detail herein.

In accordance with one aspect of the present teachings and withreference to FIGS. 4 and 5A, the index member 102 can be coupled to anintramedullary rod 110 or other suitable mounting rod that can beinserted into the distal end 20 of the left femur 12 b. A first bushing112 a can be selected from a plurality of bushings 112, examples ofwhich are shown in FIGS. 7A, 7B and 7C. Each of the bushings 112 cancouple to the index member 102 and can receive the intramedullary rod110. Each of the bushings 112 can be configured to hold the index member102 at a predetermined angle relative to a longitudinal axis 114 of theintramedullary rod 110, as discussed in greater detail.

With reference to FIGS. 7A, 7B and 7C, the plurality of bushings 112can, therefore, have varying configurations that provide for holding theindex member 102 at a range of angles relative to the longitudinal axis114 of the intramedullary rod 110 and, thus, the longitudinal axis 28 ofthe femur 12 (FIG. 3). The range of angles provided, for example, caninclude about four degrees to about seven degrees with about one degreeangle increments between four and seven degrees. It will be appreciatedthat other configurations that provide more or less angle incrementsand/or the size of the increment can be implemented as applicable.

Returning to FIG. 4, the index member 102 can have a first surfaceportion 116 that can abut the distal end 20 of the femur 12 that caninclude one or more portions of the medial condyle 24 and the lateralcondyle 22. A second surface portion 118 (FIG. 6) can be opposite thefirst surface portion 116 and one or more wall portions 120 can boundthe first surface portion 116 and the second surface portion 118. Thewall portions 120 can be configured in a shape that can be similar to aparallelogram, i.e., a quadrilateral with opposite sides parallel orsomething similar thereto. Notwithstanding, it will be appreciated inlight of the disclosure that the index member 102 can be configured withvarious suitable polygonal shapes. Moreover, the wall portions 120 canfurther include connection to and/or be integrally formed withadditional surfaces, facets, rounded portions, other suitableconfigurations and combinations thereof, that can be used to facilitatemanipulation and insertion of the index member 102 through the incision30 and/or a cannula.

The index member 102 can define a bushing receiving aperture 122. Thebushing receiving aperture 122 can include wall portions 124 that can beconfigured to abut one of the bushings 112. Each of the bushings 112 canreleasably couple to the index member 102 and/or can lock with thevarious suitable locking mechanisms thereto. One or more of the suitablelocking mechanisms can securely hold one of the bushings 112 to theindex member 102 but then can be uncoupled as needed.

The index member 102 can define one or more holes 126 that can receiveone or more complementary posts 128 that can extend from the bridgemember 104. The one or more of the holes 126 can be defined in the oneor more wall portions 120 of the index member 102 and can be sized withdifferent diameters or widths, as applicable, to receive the one or morecomplementary posts 128 on the bridge member 104. For example, a firstpost 128 a can be received by a first hole 126 a and, similarly, asecond post 128 b can be received by a second hole 126 b. The first hole126 a and the first post 128 a can have larger but complimentarydiameters or width than the second post 128 b and the second hole 126 bthat can have smaller but complementary diameters or widths, asapplicable.

The combination of the holes 126 and the complementary posts 128 can beconfigured such that only a single orientation can exist in which thebridge member 104 can couple to the index member 102. In one example, asshown in FIG. 5B, the index member 102 can be oriented in a firstposition that can abut the distal end of the left femur 12 b. Withreference to FIG. 6, the index member 102 can be re-oriented so that theindex member 102 is oriented in a second position and can abut thedistal end of the right femur 12 a. The bridge member 104 can also havea first orientation (FIG. 5B) and a second orientation (FIG. 6). Withreference to FIG. 5B, the index member 102 that can abut the left femur12 b can be configured to only accept the bridge member 104 in the firstorientation. With reference to FIG. 6, the index member 102 that canabut the right femur 12 a can be configured to only accept the bridgemember 104 in the second orientation.

Returning to FIG. 4, the bridge member 104 can define a first guideassembly 130 and a second guide assembly 132. The first guide assembly130 can include a channel 134 that can be operable to receive and/orreleasably couple a portion of the cutting guide member 106. One or moremounting mechanisms 136 can be mounted on one or more wall portions 138within the channel 134 and can releasably couple the cutting guidemember 106 to the first guide assembly 130. The one or more mountingmechanisms 136 can define one or more magnets, hook and loop fasteners,suitable adhesives and/or one or more suitable combinations thereof. Itwill be appreciated that one or more other mechanisms can be used toreleasably couple the cutting guide member 106 to the one or more wallportions 138 of the first guide assembly 130. The one or more mountingmechanisms 136 and/or other suitable mechanisms can be made of, whollyor partially, one or more suitable biocompatible materials that can besterilized.

The second guide assembly 132 can be similar to the first guide assembly130 but can be positioned on an opposite side of the bridge member 104.The second guide assembly 132 can similarly include one or more mountingmechanisms 140 that can releasably couple the cutting guide member 106to the bridge member 104. The one or more mounting mechanisms 140 and/orone or more other suitable fastening mechanisms can be mounted on one ormore wall portions 142 in the second guide assembly 132 but at alocation in the second guide assembly that can be opposite of a locationof the one or more mounting mechanisms 136 in the first guide assembly130.

With reference to FIG. 6, the one or more mounting mechanisms 136, 140in the first and the second guide assemblies 130, 132 can hold thecutting guide member 106, while the cutting guide member 106 can beadjusted relative to the distal end 20 of the femur 12 a, 12 b. Afterfinal adjustment, the cutting guide member 106 can be held by the bridgemember 104 until a relatively more secure fastener can couple to thecutting guide member 106 to the femur 12 a, 12 b, an example of which isshown in FIG. 5F. During one or more adjustments, the mountingmechanisms 136, 140 can provide for a sliding resistance that can beovercome by a medical professional (not shown) when he or sherepositions (i.e., the one or more adjustments) the cutting guide member106 relative to the bridge member 104 and/or relative to the distal end20 of the femur 12 a, 12 b.

Returning to FIG. 4, the cutting guide member 106 can generally define abody portion 142 having a first guide channel portion 144 and a secondguide channel portion 146 that can be formed through the body portion142 and can be spaced from one another. The first and the second channelportions 144, 146 can each define a generally elongated rectangularaperture through which a suitable tool 148 (FIG. 5F), such as a manualor a powered resecting tool, can be placed for cutting a portion of thedistal end 20 of the femur 12, as shown in FIG. 5C. One or more wallportions 152 of the first guide channel portions 144 can establish thefirst reference plane 154 on which a resection of the medial anteriorportion 150 of the femur 12 can be preformed. In addition, the one ormore wall portions 156 of the second guide channel 146 can establish asecond reference plane 158.

The body portion 142 of the cutting guide member 106 can define agenerally arcuate shape. The generally arcuate shape can be configuredto fit over a medial anterior portion 150 of the femur 12 a, 12 b. Itwill be appreciated in light of the disclosure the arcuate shape can beconfigured to be disposed over a medial surface and an anterior surfaceof the distal end 20 of the femur 12. In this position, the arcuateshape of the cutting guide member 106 can be disposed over a portion ofthe medial anterior corner of the femur 12.

The first cutting channel 144 and the second cutting channel 146 can beconfigured with a similar size and/or shape but can be spaced from oneanother a predetermined distance 160. In one example, the predetermineddistance 160 can be sufficient enough to provide about a threemillimeter difference in a distal cutting depth 162 (FIG. 5C) between aresection based on the first reference plane 154 and a resection basedon the second reference plane 158. By way of the above example, themedical professional can resect a portion of the femur 12 by placing thesuitable resecting tool 148 through the first guide channel 144. Theresecting tool 148 (FIG. 5F) can also cut an additional threemillimeters from the femur 12 a, 12 b by placing the resecting tool 148through the second guide channel 146 and cutting the distal end 20 ofthe femur 12 a, 12 b based on the second reference plane 158 establishedby the second guide channel 146.

The body portion 142 of the cutting guide member 106 can include aplurality of apertures 164. Each of the apertures 164 can receive one ormore fixation pins 166. The plurality of apertures 164 can include atleast a first set of apertures 164 a, a second set of apertures 164 band a third set of apertures 164 c. With the cutting guide member 106secured to the femur 12 a, 12 b with the fixation pins 166 either in thefirst set of apertures 164 a or in the second set of apertures 164 b,the cutting guide member 106 can still be removed from the femur 12without the need to remove the fixation pins 166. In this regard, thefirst set of apertures 164 a and the second set of apertures 164 b areconfigured so as to permit the cutting guide member 106 to be lifted offthe femur 12 a, 12 b with the fixation pins 166 remaining, as shown, forexample, in FIG. 5D.

In contrast, the third set of apertures 164 c are configured such thatwhen the cutting guide member 106 is fixed to the femur 12 using thethird set of apertures 164 c, the cutting guide member 106 can only beremoved from the femur 12 a, 12 b by removing the fixation pins 166 fromthe third set of apertures 164 c. As such, securing the cutting guidemember 106 to the femur 12 a, 12 b with the third set of apertures 164 c(FIG. 5F) relative to the first set of apertures 164 a (FIG. 5C) can beshown to provide a relatively more robust securement during a resectionprocedure. The fixation pins 166, however, need to be removed from thethird set of apertures 164 c before the cutting guide member 106 can beremoved from the femur 12.

In one example, when one or more of the fixation pins 166 are in thefirst set of apertures 164 a, the fixation pins 166 are disposedgenerally normal to an exterior surface 168 of the femur 12 a, 12 b.Because the fixation pins 166 are generally normal to the exteriorsurface 168, the cutting guide member 106 can be secured from rotationand/or displacement in directions that are generally parallel to thelongitudinal axis 114 (FIG. 6) of the femur 12 a, 12 b.

The cutting guide member 106, however, can be pulled away from theexterior surface 168 of the femur 12 a, 12 b so that the cutting guidemember 106 can be, for example, repositioned. In this regard, thecutting guide member 106 can be advanced up (i.e., in a superiordirection) or down (i.e., in an inferior direction) relative to thelongitudinal axis 114 of the femur 12 to adjust the reference planes154, 158 for a more deep or a more shallow resection of the distal end20 of the femur 12 (see, e.g., FIGS. 5C, 5D, 5E and 5F). In doing so,the first set of apertures 164 a can release the fixation pins 166 andthe second set of apertures 164 b can receive the fixation pins 166 sothat the cutting guide member 106 can be located in a more superiorposition. In contrast, the third set of apertures 164 c in the cuttingguide member 106 can be at an angle 169 (FIG. 5D) that, in certainaspects, is not parallel to the first and second set of apertures 164 a,164 b. The configuration of the angle 169 allows the cutting guidemember 106 to be relatively more securely fastened to the femur 12 a, 12b in that the cutting guide member 106 may not lift off the femur 12 a,12 b, while the fixation pins 166 are received by the third set ofapertures 164 c.

With reference to FIG. 5F, the suitable resecting tool 148 can be manualor powered. A powered implementation of the resecting tool 148 can beelectrical and/or pneumatic. A portion of the resecting tool 148, forexample, a blade 172 can index off (e.g., abut while reciprocating) oneof the first cutting channel 144 or the second cutting channel 146formed in the cutting guide member 106. In this regard, the resectingtool 148 can cut along (or cut generally parallel to) the referenceplane 154 established by the first cutting channel 144 or the secondreference plane 158 established by the second cutting channel 146.

With reference to FIG. 5A, the intramedullary rod 110 can be configuredto fit into an intramedullary canal 176. In one example, theintramedullary rod 110 can be inserted in a hole 178 formed between thecondyles 22, 24 of the distal end 20 of the femur 12. It will beappreciated in light of the disclosure that the intramedullary rod 110can be inserted in the hole 178, a sufficient distance so that variouscomponents can be installed on an end of the intramedullary rod 110 thatis not disposed in the intramedullary canal 176. A portion of theintramedullary rod 110 can be configured to accept a removable handle180 that can be used to facilitate installation and/or removal of theintramedullary rod 110 in and from the intramedullary canal 176 and/orto facilitate installation or removal of various components on and fromthe intramedullary rod 110.

With reference to FIG. 4A, a cross-section 182 of the intramedullary rod110 can be generally oval but can include one or more portions that canbe removed from an otherwise whole oval-shape. In one example, twov-shaped grooves 184 can be formed at generally opposite sides of theintramedullary rod 110. The v-shaped grooves 184 or other suitableportions removed from the intramedullary rod 110 can provide for ananti-rotation functionality. In this regard, one or more components thatcan be inserted on the intramedullary rod 110 can be keyed (i.e.,include key to interconnect with one of the grooves 184) to provide ananti-rotation functionality.

The various components of the cutting guide assembly 100 can be made ofone or more suitable bio-compatible materials. One example of abio-compatible material is a cobalt chrome alloy. Other examples caninclude titanium and suitable polymers such as an ultra high molecularweight polyethylene.

With reference to FIGS. 4, 7A, 7B, 7C, the bushing 112 can couple theintramedullary rod 110 to the index member 102. The bushing 112 can beconfigured such that the intramedullary rod 110 can be held at the angle170 relative to the index member 102. In this regard, the angle 170 canrange from negative four to positive four degrees. As explained above,one bushing 112 a can be selected from the plurality of bushings 112 toselect a predetermined angle between the intramedullary rod 110 and theindex member 102. As such, each bushing 112 of the plurality of bushings112 can be configured to provide a different angle between thelongitudinal axis 114 of the intramedullary rod 110 and the index member102.

In operation, one or more incisions 30 can be made near the knee joint10 to provide access to a portion of the distal end 20 of the femur 12,as shown in FIG. 3. With reference to FIGS. 4-5F, the intramedullary rod110 can be mounted into the hole 178 (FIG. 5C) formed in the distal end20 of the femur 12. The handle 180 can be removed from theintramedullary rod 110 to provide access and to allow for components tobe inserted over the intramedullary rod 110. One of the bushings 112 canbe selected from the plurality of bushings 112 (FIGS. 7A-7C) toestablish, for example, the reference plane 108, 154, 158 that isdisposed at the angle 170 (FIGS. 7A-7C) relative to the longitudinalaxis 114 of the intramedullary rod 110. The angle 170 can be a suitablevalgus angle as determined by the medical practitioner.

When one of the proper bushings 112 is selected, the bushing 112 can becoupled to the index member 102. The bridge member 104 can be coupled tothe index member 102. The cutting guide member 106 can then be coupledto the index member 102 and held in place in the first guide assembly130 by the one or more mounting mechanisms 140 or other suitablefasteners. The index member 102, the bridge member 104 and the cuttingguide member 106 can be inserted over the intramedullary rod 110 via thebushing 112 and slid down the intramedullary rod 110 to abut the distalend 20 of the femur 12.

When the index member 102 abuts the distal end 20 of the femur 12, thecutting guide member 106 can be manipulated so as to be positionedaround the medial anterior portion 150 of the distal end 20 of the femur12. In this regard, the arcuate shape of the cutting guide member 106can be disposed around the medial anterior portion 150 of the femur 12a, 12 b to provide the access to that portion of the femur 12 a, 12 b.

The cutting guide member 106 can be releasably coupled to the bridgemember 104 so as to provide a sliding resistance between the cuttingguide member 106 and the bridge member 104. It will be appreciated inlight of this disclosure that the medical professional can overcome thesliding resistance as he or she manipulates the cutting guide member 106relative to the femur 12 as he or she positions the cutting guide member106 about the medial anterior portion of the distal end 20 of the femur12.

With reference to FIG. 5F, when the cutting guide member 106 ispositioned as described above, one or more of the fixation pins 166 canbe driven into the first set of apertures 164 a formed on the bodyportion 142 of the cutting guide member 106. One or more additionalfixation pins 166 can be inserted through the third set of apertures 164c formed in the body portion 142 of the cutting guide member 106.Resection of the distal end 20 of the femur 12 a, 12 b along the firstreference plane 154 established by the first channel portion 144 canoccur with the cutting guide member 106 secured to the femur 12 with thefixation pins 166 in one of the first set of apertures 164 a, the secondset of apertures 164 b, the third set of apertures 164 c and one or morecombinations thereof. When the fixation pins 166 are received in thethird set of apertures 164 c, the fixation pins 166 can be removed so asto allow the cutting guide member 106 to be lifted off the fixation pins166 received in the first set of apertures 164 a and, for example,advanced up in a direction superior to the distal end 20 of the femur 12and then re-secured by allowing the second set of apertures 164 b toreceive the same fixation pins 166. In this regard, the cutting guidemember 106 is advanced up the femur 12 a, 12 b a predetermined distance.

Prior to or after the advancement of the cutting guide member 106 of thefemur 12 a, 12 b, the medical practitioner can continue to resect thedistal end 20 of the femur 12 a, 12 b using the first cutting channel144 or the second cutting channel 146, which can be at a predetermineddistance from the first cutting channel 144.

While specific aspects have been described in this specification andillustrated in the drawings, it will be understood by those skilled inthe art in light of the disclosure that various changes can be made andequivalents can be substituted for elements thereof without departingfrom the scope of the present teachings, as defined in the claims.Furthermore, the mixing and matching of features, elements and/orfunctions between various aspects of the present teachings are expresslycontemplated herein so that one skilled in the art will appreciate fromthe present teachings that features, elements and/or functions of oneaspect of the present teachings may be incorporated into another aspect,as appropriate, unless described otherwise above. Moreover, manymodifications may be made to adapt a particular situation, configurationand/or material to the present teachings without departing from theessential scope thereof. Therefore, it is intended that the presentteachings not be limited to the particular aspects illustrated by thedrawings and described in the specification as the best mode presentlycontemplated for carrying out the present teachings but that the scopeof the present teachings will include many aspects and examplesfollowing within the foregoing description and the appended claims.

1. A method of positioning a femoral cutting guide on a distal end of afemur that establishes at least a first reference plane to perform adistal femoral planar cut, the method comprising: inserting a mountingmember into an intramedullary canal of the femur; coupling a bridgemember to the mounting member, the bridge member having a bridgechannel; placing a cutting guide member over a medial anterior portionof the distal femur, the cutting guide member having a first channelthat establishes the first reference plane; inserting a wall of thebridge channel into the first channel of the cutting guide member; andovercoming a resistance generated by a mounting mechanism between thebridge member and the cutting guide member by positioning the cuttingguide member relative to the femur.
 2. The method of claim 1, whereinplacing the cutting guide member over the medial anterior portion of thedistal femur includes placing a portion of the cutting guide member overa medial surface and an anterior surface of the femur so as to at leastbe disposed over a portion of a medial anterior corner of the femur. 3.The method of claim 1, wherein overcoming a resistance generated by themounting mechanism includes moving the cutting guide member relative tothe femur in at least one of an anterior posterior direction, a mediallateral direction, a rotation about a longitudinal axis of the femur andcombinations thereof.
 4. The method of claim 1, further comprisinginhibiting movement of the cutting guide member in a superior distaldirection relative to the femur when the cutting guide member isconnected to the bridge member.
 5. The method of claim 1, furthercomprising passing the mounting member through an offset opening betweenfirst and second opposing surfaces of an index member.
 6. The method ofclaim 5, further comprising inserting a first elongated post of thebridge member into a first aperture on a peripheral wall of the indexmember.
 7. The method of claim 6, further comprising inserting a secondelongated post of the bridge member into a second aperture on theperipheral wall of the index member, the second elongated post andsecond aperture having different cross-sectional sizes than the firstelongated post and first aperture.
 8. The method of claim 7, furthercomprising engaging the first surface of the index member to the distalend of the femur when the femur is a right femur, and engaging thesecond surface of the index member to the distal end of the femur whenthe femur is a left femur.
 9. The method of claim 1, wherein overcomingthe resistance generated by a mounting mechanism between the bridgemember and the cutting guide comprises overcoming sliding resistanceprovided by magnets.
 10. The method of claim 1, wherein overcoming theresistance generated by a mounting mechanism between the bridge memberand the cutting guide comprises overcoming sliding resistance providedby hook and loop fasteners.
 11. The method of claim 1, furthercomprising coupling the index member to the mounting member at aselected angle therebetween using a bushing.
 12. A method of positioninga femoral cutting guide on a distal end of a femur that establishes atleast a first reference plane to perform a distal femoral planar cut,the method comprising: passing a mounting rod into a keyed bushingcoupled to an offset opening through first and second opposing surfacesof an index member; inserting the mounting rod into an intramedullarycanal of the femur; inserting first and second elongated posts of abridge member into corresponding first and second apertures in aperipheral wall of the index member; placing a cutting guide member overa medial anterior portion of the distal femur, the cutting guide memberhaving a first channel that establishes the first reference plane;inserting a wall of a bridge channel of the bridge member into the firstchannel of the cutting guide member; and providing a sliding resistancebetween the bridge member and the cutting guide member by a mountingmechanism.
 13. The method of claim 12, wherein the first and secondapertures have cross-sections of different sizes.
 14. The method ofclaim 12, further comprising engaging the first surface of the indexmember to the distal end of the femur when the femur is a right femurand engaging the second surface of the index member to the distal end ofthe femur when the femur is a left femur.
 15. The method of claim 12,further comprising establishing a second reference plane spaced apartfrom the first reference plane in a direction that is superior to thefirst reference plane.
 16. The method of claim 15, wherein the secondreference plane passes through a second channel of the cutting guidemember.
 17. The method of claim 12, wherein the cutting guide member hasan arcuate shape configured to be positioned over a portion of a medialsurface and a portion of an anterior surface of the femur at a medialanterior corner of the distal end of the femur.
 18. The method of claim12, further comprising selecting the bushing from a plurality ofbushings for coupling the index member to the mounting rod at a selectedangle therebetween.
 19. A method of positioning a femoral cutting guideon a distal end of a femur that establishes at least a first referenceplane to perform a distal femoral planar cut, the method comprising:passing a mounting rod into a keyed bushing coupled to an offset openingthrough first and second opposing surfaces of an index member; insertingthe mounting rod into an intramedullary canal of the femur; insertingfirst and second elongated posts of a bridge member into correspondingfirst and second apertures in a peripheral wall of the index member, thefirst and second elongated posts having different cross-sections;placing a cutting guide member over a medial anterior corner of thedistal femur, the cutting guide member having first and second paralleland arcuate channels that establish the first reference plane and asecond reference plane; inserting a wall of a bridge channel of thebridge member into one of the first and second channels of the cuttingguide member; and engaging the first surface of the index member to thedistal end of the femur when the femur is a right femur, and engagingthe second surface of the index member to the distal end of the femurwhen the femur is a left femur.
 20. The method of claim 19, furthercomprising providing sliding resistance between the bridge member andthe cutting guide member by a mounting mechanism.